feat(zeebe): support engines property

`engines` is a new property that allows templates to declare
compatibility with other run-time provided engines.

Closes #146

packages/zeebe-element-templates-json-schema/src/defs/engines.json

@@ -0,0 +1,19 @@
+{
+  "$id": "#/engines",
+  "type": "object",
+  "description": "Defines the compatibility of this element template with different engines. Keys are engine names, values are semantic version ranges.",
+  "default": {},
+  "examples": [
+    {
+      "camunda": "^8.5"
+    }
+  ],
+  "properties": {
+    "camunda": {
+      "$id": "#/engines/camunda",
+      "type": "string",
+      "description": "A semantic version range that denotes compatible Camunda versions.",
+      "default": ""
+    }
+  }
+}

packages/zeebe-element-templates-json-schema/src/schema.json

@@ -28,6 +28,9 @@
           "$ref": "#/definitions/properties",
           "$id": "#/properties"
         },
+        "engines": {
+          "$ref": "src/defs/engines.json"
+        },
         "icon": {
           "$ref": "src/defs/icon.json"
         },

packages/zeebe-element-templates-json-schema/test/fixtures/engines-invalid-version.js

@@ -0,0 +1,41 @@
+export const template = {
+  'name': 'Engines Invalid Versions',
+  'id': 'foo',
+  'appliesTo': [
+    'bpmn:Task'
+  ],
+  'engines': {
+    'camunda': [ '8.5' ],
+  },
+  'properties': [],
+};
+
+export const errors = [
+  {
+    dataPath: '/engines/camunda',
+    keyword: 'type',
+    message: 'should be string',
+    params: {
+      type: 'string'
+    },
+    schemaPath: '#/properties/engines/properties/camunda/type'
+  },
+  {
+    keyword: 'type',
+    dataPath: '',
+    schemaPath: '#/oneOf/1/type',
+    params: {
+      type: 'array'
+    },
+    message: 'should be array'
+  },
+  {
+    keyword: 'oneOf',
+    dataPath: '',
+    schemaPath: '#/oneOf',
+    params: {
+      passingSchemas: null
+    },
+    message: 'should match exactly one schema in oneOf'
+  }
+];

packages/zeebe-element-templates-json-schema/test/fixtures/engines-invalid.js

@@ -0,0 +1,39 @@
+export const template = {
+  'name': 'Engines Invalid',
+  'id': 'foo',
+  'appliesTo': [
+    'bpmn:Task'
+  ],
+  'engines': '8.5',
+  'properties': [],
+};
+
+export const errors = [
+  {
+    dataPath: '/engines',
+    keyword: 'type',
+    message: 'should be object',
+    params: {
+      type: 'object'
+    },
+    schemaPath: '#/properties/engines/type'
+  },
+  {
+    keyword: 'type',
+    dataPath: '',
+    schemaPath: '#/oneOf/1/type',
+    params: {
+      type: 'array'
+    },
+    message: 'should be array'
+  },
+  {
+    keyword: 'oneOf',
+    dataPath: '',
+    schemaPath: '#/oneOf',
+    params: {
+      passingSchemas: null
+    },
+    message: 'should match exactly one schema in oneOf'
+  }
+];

packages/zeebe-element-templates-json-schema/test/fixtures/engines-no-camunda.js

@@ -0,0 +1,13 @@
+export const template = {
+  'name': 'Engines Valid',
+  'id': 'foo',
+  'appliesTo': [
+    'bpmn:Task'
+  ],
+  'engines': {
+    'other': '^1.3-beta.0'
+  },
+  'properties': []
+};
+
+export const errors = null;

packages/zeebe-element-templates-json-schema/test/fixtures/engines.js

@@ -0,0 +1,14 @@
+export const template = {
+  'name': 'Engines Valid',
+  'id': 'foo',
+  'appliesTo': [
+    'bpmn:Task'
+  ],
+  'engines': {
+    'camunda': '8.5',
+    'other': '^1.3-beta.0'
+  },
+  'properties': [],
+};
+
+export const errors = null;

packages/zeebe-element-templates-json-schema/test/spec/validationSpec.js

@@ -389,6 +389,19 @@ describe('validation', function() {
 
       testTemplate('placeholder-invalid-type');
     });
+
+
+    describe('engines', function() {
+
+      testTemplate('engines');
+
+      testTemplate('engines-no-camunda');
+
+      testTemplate('engines-invalid');
+
+      testTemplate('engines-invalid-version');
+    });
+
   });
 
 });